A Whitehall counter-terrorism unit is targeting the BBC and other media organisations as part of a new global propaganda push designed to "taint the al-Qaida brand", according to a secret Home Office paper seen by the Guardian.

The document also shows that Whitehall counter-terrorism experts intend to exploit new media websites and outlets with a proposal to "channel messages through volunteers in internet forums" as part of their campaign.

The strategy is being conducted by the research, information and communication unit, [RICU] which was set up last year by the then home secretary, John Reid, to counter al-Qaida propaganda at home and overseas. It is staffed by officials from several government departments.

The report, headed, Challenging violent extremist ideology through communications, says: "We are pushing this material to UK media channels, eg, a BBC radio programme exposing tensions between AQ leadership and supporters. And a restricted working group will communicate niche messages through media and non-media."

The disclosure that a Whitehall counter-terrorism propaganda operation is promoting material to the BBC and other media will raise fresh concerns about official news management in a highly sensitive area.

The government campaign is based upon the premise that al-Qaida is waning worldwide and can appear vulnerable on issues such as declining popularity; its rejection by credible figures, especially religious ones, and details of atrocities.

The Whitehall propaganda unit is collecting material to target these vulnerabilities under three themes. They are that al-Qaida is losing support; "they are not heroes and don't have answers; and that they harm you, your country and your livelihood".

The RICU guidance, dated July 21 2008, says that the material is primarily aimed at "overseas communicators" in embassies and consulates around the world, confirming the global scale of the Whitehall counter-terrorist propaganda effort now underway.

But it also says that other partners should be encouraged to integrate this work into their communications at home as well: "It is aimed primarily (but not exclusively) at those working with overseas influencers and opinion formers."

The first dossier of material being despatched to diplomatic posts worldwide cites condemnation of al-Qaida from Sayyid Imam al-Sharif aka Dr Fadi, a former leader of Egyptian Islamic Jihad, and Salman Abu-Awdah, a leading Saudi scholar who has published an open letter to Osama bin Laden calling al-Qaida's aims illegitimate and immoral. It notes that groups like Hamas and Hezbollah are now keen to distance themselves from al-Qaida.

In a section headed "AQ has suffered military defeat in ..." it adds "use advisedly - avoid suggesting that AQ is no longer a threat. We are not claiming victory over AQ. We are stressing their declining support".

The dossier says that al-Qaida has been definitively expelled from large areas of Iraq and has lost ground in Afghanistan. It quotes CIA director Michael Hayden's claim in May that al-Qaida had been essentially defeated in Iraq and Saudi Arabia and was now "on the defensive throughout much of the rest of the world," but describes this as a "strikingly upbeat assessment of the organisation".

It highlights the fact that Mohammed Hamid, who was convicted in February for recruiting and radicalising young men to fight against the west, was a former crack addict.

The document also notes that al-Qaida has to "feed its new franchises with propaganda to keep the 'brand' alive at all costs". It says that it is focused on Palestine - to the discomfort of the Palestinians - because it has failed in Iraq and is now pronouncing on issues as diverse as Egyptian trade unions and climate change in a desperate attempt to remain relevant.

The "material" is a mixture of recent news reports and articles from Arabic, Middle Eastern and North African news sources illustrating the theme of "AQ is in decline" as well as articles from the New York Times, the Observer, Newsweek and British and American websites.

The RICU guidance note says the dossier has been drafted with support from Whitehall press officers "on how best to tailor such material for media engagements, presenting information to ministers, or to other stakeholders. It is in a separate, unclassified format to make it the sort of product that a minister or a press officer could use before an interview; or that could be given as a crib sheet for trusted contacts," says the classified document.